Expansible tool.



A; A. MARTELL.

EXPANSIBLE TOGL. APPLICATION FILED APR.21, 191s.

Patented Oct. 17, 1916.

' itfkno'un tlia'tl, ALnnnT A. MARTELL,

e county of Bristol and 7 etts; have invented a new nsible Tool, of which the hegem-ralobject of my invention is to increase the efficiency and accuracy of ex- ,pansibletools, h

obj e'ct of my invention is are in' rf with nieaiis to prevent l th'eb ades.

remitto provide means for ut surfaces." to provide the tool with f used with ditferent sizes objec ill be pointed out below. tuition consists partly in'ineans for K the 'ei'ids of the blades inwardly. "partly in rtiuiiiliiig an edge of'the blades aml partiv in a sleeve with an exterior of 'ditl'erentsi/esand partlyin other featuresdescribed below.

In the drawings: Figure 1 is a central longitudinal sectional view of a tool embod \'ing my invention; 2 is a central longitudinal sectional view of the body of the tool shown in Fig. 1; Fig. 3 is a section on line 33 of Fig. 1: Fig. l is a perspective view of one of the blades; and Fig. 5 is a detail illustrating the principle of construction and operation.

By way of example I disclose an expansible tool in the form of a reanier. The

body or shank A has enlarged portion A provided with longitudinal recesses A to receive the blades. Threaded portions 64 and a are provided to cooperate with the clamping nuts and at one end the; hank 1s interiorly threaded at a to coiipeipte with any suitable pilot. The shank is also provided with circular holes a in line with recesses A Each blade I3 is provideck witlr engaging surfaces 1'), b, b and with the cutting edge 7/ and the rounded edge 12 Whose function is to burnishthe surface which has been cut. This rounded edge is so located that it will properly engage the cut surface and I preferably have it extend from the rear end of the blade about as far as shown in the drawing. Wedges d, (Z, (Z are provided, each comprising a circular portion to enter .QLBER'I ASMARTEL'LQOF MANSFIEL assacn smwgfl f EXPANSIBLE TOOL.

Specification of Letters Patent.

to prevent bulging of the bladest the nisible tool such, forcx PatentettOct'. inf ate;

Application flied April .21, 1915. Serial hl'o. 22,933.

the appropriate hole a cam surface to engage the appropriate engaging surface- I o i Z). 6 or Zgon the blade. U An important purpose of invention 'is center and this I accomplishlbylhaving the blade engage the nnddle. 'wedg H "such and then screwing up the dam j gjn t E and F so that the ends of the fbl'adeaie forced inwardly with theJresult tha the blade is held tightly: ag nst the" center wedge withno possibilitjflof oi r for inward bulging. I \Vhenth'efblade"has been so 'adjustet'l'its cutting'and burin l' iiig are groundofl to bepa'rallel with th elongi tudinal' axis of the tool. 'Th ebe'nding' iii- Award ofthe' ends of the'blade i'sfdiie inft he form shown to the fact jtha't" the plane 'offthe cam surface 5 is nearer to the pl'a-1'ief bf the cam surface 3) than dis enser,-are.. cam surface 'The 'peculi'a'r" relative-hr i'angement of cam surfaces inight behad for theset of cam surfaces onthe Wedges,

but I have illustrated'the"arrangementfor the set of cam surfaces on the blade.

Another important-feature of my invention is the rear circular guide G which is provided with four portions 9, g, g and 9 whose sectional dimensions vary to suit different sizes of cutting diameter of the tool.

In the drawing the portion 9 is of the small est' dimension, the next larger being portion g, then portion and then portion 9 but I prefer to have portion in the location shown as this is more convenient and it will be clear that if desired the portion 9 1%21) be innermost or ii. desired the guide n ay he slid off the shank and reversed so that portion is innermost. In this Way I provide a suitable guide for the tool during the latter part of its cutting action. e

I do not claim the guide sleeve assuch in this application as I intend to make it the subject of another application.

I do not claim the burnishing feature in this application as I intend to make that the subject of another application.

What I claim is:

1. An expansible tool comprising a body provided with three engaging portions; 2. blade having three engaging portions c'0rresponding to the engaging portions of the body to engage said portions of the body; and means to adjust sbly'clamp said blade with. said portions of the latter to saidfbddy with all of the engaging portions of thelatter in engagement with all of the engaging )ortions of the blade.

2. An expansi le tool comprising a body formed with a' plurality of longitudinal pblade reserving slots; a blade mounted 1n each slot made with a. cam surtace near each end and with an intermediate cam surface; blade clamping means adjustably mounted on said body for engaging the end of the blades; and three parallel cam surfaces in each body slot two of which co- 0 erate with the end cam surfaces of the b ade of'saidslot and the other cooperating with the intermediate cam surface of the blade so that the blade clamping means bends the ends of each blade inward when tightenedon to the latter. I p

3. An-expansible tool comprising a body provided with threeengaging portions; a blade having three engaging portions correspondingto the engaging portions ofthe bodyhtoengage said portions of thebody; and means toclamp said blade to said body said portions of all the former, the cutting edge of the blade being parallel to the 1011 gitudinal axis. of the tool and said clampmg} means adapted to ad ust said blade. ho i 1y transversely of said body. 4. An expansible tool comprising a body formed with a plurality of longitudinal.

blade receiving slots; blade clamping means engaging provided with two end engaging portions and an intermediate engaging portion; a blade provided with an intermediate, and two end, engaging portions to engage said portions of the body; and means to adjustably clamp said blade to said body with said intermediate portion in engagement with the corresponding engaging portion of the body. v

6. An expansible tool comprising a body provided with three engaging portions; a blade having three engaging portions corresponding to the engaging portions of the body to engage said portions of the body, one of said portions of the blade, when the latter is unclamped, being out of engagement with the corresponding portion of the body; and clamping means to spring said one portion into engagement with the corresponding portion 011 the body and to retain all said portions of the body in engagement with all said corresponding portions of the blade.

ALBERT A. MARTELL. 

